import java.util.*;
import java.util.zip.*;
import java.util.List;
import java.util.regex.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;
import java.util.concurrent.locks.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.table.*;
import java.io.*;
import java.net.*;
import java.lang.reflect.*;
import java.lang.ref.*;
import java.lang.management.*;
import java.security.*;
import java.security.spec.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.imageio.*;
import java.math.*;
class main {

static interface IContentsIndexedList2<A> extends List<A> {
  TreeSet<HasIndex> indicesOf_treeSetOfHasIndex(Object o);
}
static class HasIndex implements Comparable<HasIndex> {
  int idx;
  
  HasIndex() {}
  HasIndex(int idx) {
  this.idx = idx;}
  
  public int compareTo(HasIndex h) {
    return idx-h.idx;
  }
}
}